1. Field of the Invention
This invention relates to the prevention of fouling of substrates in marine environments and particularly to the prevention of fouling coupled with corrosion inhibition by the application of a coating of technetium-99 to the substrate.
2. Discussion of the prior Art
Marine organisms, e.g. algae, sea worms, sea plants, barnacles, crustacea, etc., cause millions of dollars damage each year to underwater environments such as instrument transducers and other underwater instrumentation, buoys, submarine ballast tanks, sea water gauges, underwater sonar, and the like by forming growths of the marine organisms on the surfaces of these in-the-water devices. Eventually there results undesirable and damaging fouling which, at the least is very expensive and time consuming to remove, or may totally destroy the usefulness of the device.
The prior art has developed numerous anti-fouling paints for application to in-the-water devices, particularly ship hulls. However, these anti-fouling paints eventually peel off from the surface during use and therefor only have a limited life expectancy requiring frequent costly shutdowns and reapplications. Particularly in the case of stainless steel devices, adhesion of the anti-fouling paints is unsatisfactory. Also, anti-fouling paints, unless applied in relatively thick coatings are subject to small cracks which expose the surface of the coated device and allow penetration by corrosive salt water and marine organisms. Even very minute cracks in the paint can result in damage to the coated device. Anti-fouling paints have the additional disadvantage in that the paint can easily be scratched or scraped off of the surface. Also, anti-fouling paints too frequently create a health hazard to non-harmful sea life because of the nature of the poisonous substances in the paint. Fouling and corrosion prevention is particularly important for underwater instrumentation having moving parts, such as transducers of the flexible diaphragm type, or liquid level measuring devices utilizing a sliding rod. Such devices become totally ineffective when fouled by marine growth.
The problem of keeping underwater instrument transducers and other underwater instrumentation, etc., free of marine growth has heretofore remained unsolved.